Aircraft Fuel Tank Inerting Control for Mission-Adaptive Gas Flow
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Solution Overview
Problem
Conventional inerting systems for aircraft fuel tanks are oversized for typical mission profiles, leading to excessive inerting gas flow and increased fuel consumption and operational costs, as they are designed to meet more restrictive parameters than those encountered during real missions.
Innovation Solution
A method to control the inerting system by determining actual mission parameters and adjusting the inerting gas flow using a weighting coefficient based on the ratio of real mission parameters to certified standard mission profile values, allowing for real-time adaptation of the inerting gas flow to match actual needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the inerting system is designed according to the certified standard mission profile with more stringent parameters, then the safety compliance is improved, but the fuel consumption and operational costs increase due to oversized inerting gas flow
Solution Approach 1:
The inerting system dynamically adjusts the inerting gas flow rate based on real-time comparison between actual mission parameters and certified standard mission profile parameters. The weighting coefficient varies continuously from 0.5 to 1.0 depending on the ratio of actual to standard parameters, enabling the system to adapt to different flight conditions while maintaining safety compliance and reducing fuel consumption during typical operations
Solution Approach 2:
The system changes the operational parameters of the inerting gas generator by adjusting the inerting gas flow rate according to the weighting coefficient. This parameter adjustment allows the system to operate at reduced flow rates (50-100% of standard profile requirements) during actual missions that are less stringent than the certified standard profile, thereby reducing fuel consumption while maintaining adequate safety margins
2Reliability
If the inerting system uses a fixed flow rate based on the certified standard mission profile, then the safety requirement is met, but the system becomes oversized and generates excessive inerting gas flow for typical missions
Solution Approach 1:
The control unit continuously monitors actual mission parameters (descent rate, climb rate, altitude, free volume) and compares them with the certified standard mission profile parameters. Based on this feedback loop, the system calculates the weighting coefficient and adjusts the inerting gas flow rate accordingly, ensuring safety requirements are met while avoiding excessive gas generation during typical operations
Solution Approach 2:
The system applies partial action by injecting inerting gas at 50-100% of the flow rate required by the certified standard mission profile, depending on the actual mission conditions. This partial action is sufficient to meet safety requirements during typical missions while avoiding the excessive gas generation that would occur with full-flow-rate operation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces fuel consumption and operational costs by injecting the minimum necessary inerting gas flow while ensuring compliance with safety regulations, as the inerting system injects a flow rate proportional to the actual mission requirements, thereby optimizing gas usage.
Implementation Method 1
The OBIGGS system includes at least one air separation module containing, for example, permeable membranes, such as polymer membranes, through which an airflow passes. Due to the different permeabilities of the membrane to nitrogen and oxygen, the system divides the airflow to produce a nitrogen-rich airflow and an oxygen-rich airflow.
Data Source
Figure 1
AI summary
Method for controlling an inerting system (1) designed to inject, during a real mission of an aircraft, a flow of inerting gas into at least one fuel tank (2) of said aircraft. According to the invention, the method consists in carrying out the steps consisting in: determining a value of at least one parameter of the real mission of the aircraft at a given instant; - make the ratio between the determined value of the parameter of the real mission and a value of an equivalent parameter at the given instant of a certified typical mission profile, and deduce a weighting coefficient therefrom; - weighting with the weighting coefficient a value of the flow of inerting gas recommended by the certified type mission profile for the value of the equivalent parameter at the given moment, in order to determine a flow of inerting gas to be injected adapted to the need for the real mission at the given moment; - control the inerting system to inject the determined inerting gas flow at the given moment.